Install Instructions

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Application 303V-2
Mechanical
Electrical
The Zone Valve Control 303V operates a two heating zones and a domestic hot water tank. When a thermostat calls
for heat, the zone valve opens and the system pump and the boiler turn on once the zone valve end switch closes. The
domestic hot water tank is heated using a pump. When priority is selected, the heating zones are shut off while the
hot water tank is heated.
Legend
A1 = DHW Tank Aquastat
B1 = Modulating Condensing Boiler
BP = Boiler Pump
PS = System Pump
P1 = Zone 1 DHW Tank Pump
T1 = WiFi Thermostat 561, 562or 563
T2 = Generic Bi-Metallic Strip
Thermostat
V1 = 2-Wire Zone Valve
V2 = 4-Wire Zone Valve
Included 510 Ω
resistor must be
installed when
using power
stealing thermostats
(e.g. Thermostat T2)
LN
Power
LN
B1
PS
P1 V1 V2
A1
BP
303V
End switch jumper required for Zone
1 when using a pump and Zone
Valve End Switch DIP = On
Away C R Rh W R W
MOD
XX
tN4
T1 T2 T3 T4 T5 T6
A
DHW CRW
BOILER T-STAT 1T-STAT 2T-STAT 3
-
+
tN4
A
CRW
tN4
A
CRW
T-STAT 4
tN4
A
CRW
T-STAT 5
tN4
A
CRW
T-STAT 6 EXPANSION
tN4
A
CRW
tN4
A
BCDE
FUSE 2 FUSE 1
END
SWITCH
MOTOR
POWER
PRIORITYSYS PUMP
ROOM
RESPONSE
ZONE 1
70 80
9060
50 100
MOD MAX %
END
SWITCH
MOTOR
ZONE 2
END
SWITCH
MOTOR
ZONE 3
END
SWITCH
MOTOR
ZONE 4
END
SWITCH
MOTOR
ZONE 5
END
SWITCH
MOTOR
ZONE 6
MASTER MEMBER
OFF
OFF
OFF
T-STAT 1 PRIORITY : ON
EXERCISING : ON
POST PURGE : ON
MOD BOILER : 0-10V
SYSTEM PUMP DURING PRIORITY: ON
SYSTEM PUMP WITH MEMBER CALL: ON
ZONE VALVE END SWITCHES: ON
RESERVED
120 VAC
POWER PUMP PUMP 1
SYSTEM PRIORITY
LNLNLN
OFF
OFF
OFF
4-20 mA
+T-T
DHW
-
B1
A1
T1
P1L N PS
V1
V2
T2
DIP Switches
Master
T-stat 1 Priority On
Exercising On
Post Purge On
Mod Boiler - depends on boiler
System Pump During Priority Off
System Pump With Member Calls Off
Zone Valve End Switches On